This version of the documentation is outdated!
Click here for the latest released version.
geolocation.watchPosition
Watches for changes to the device's current position.
var watchId = navigator.geolocation.watchPosition(geolocationSuccess,
[geolocationError],
[geolocationOptions]);
Parameters
- geolocationSuccess: The callback that is called with the current position.
- geolocationError: (Optional) The callback that is called if there was an error.
- geolocationOptions: (Optional) The geolocation options.
Returns
- String: returns a watch id that references the watch position interval. The watch id can be used with
[geolocation.clearWatch](geolocation.clearWatch.html)
to stop watching for changes in position.
Description
Function geolocation.watchPosition
is an asynchronous function. It returns the device's current position when a change in position has been detected. When the device has retrieved a new location, the [geolocationSuccess](parameters/geolocationSuccess.html)
callback is invoked with a [Position](Position/position.html)
object as the parameter. If there is an error, the [geolocationError](parameters/geolocationError.html)
callback is invoked with a [PositionError](PositionError/positionError.html)
object.
Supported Platforms
- Android
- BlackBerry WebWorks (OS 5.0 and higher)
- iPhone
- Windows Phone 7 ( Mango )
Quick Example
// onSuccess Callback
// This method accepts a `Position` object, which contains
// the current GPS coordinates
//
function onSuccess(position) {
var element = document.getElementById('geolocation');
element.innerHTML = 'Latitude: ' + position.coords.latitude + '<br />' +
'Longitude: ' + position.coords.longitude + '<br />' +
'<hr />' + element.innerHTML;
}
// onError Callback receives a PositionError object
//
function onError(error) {
alert('code: ' + error.code + '\n' +
'message: ' + error.message + '\n');
}
// Options: retrieve the location every 3 seconds
//
var watchID = navigator.geolocation.watchPosition(onSuccess, onError, { frequency: 3000 });
Full Example
<!DOCTYPE html>
<html>
<head>
<title>Device Properties Example</title>
<script type="text/javascript" charset="utf-8" src="cordova-1.6.1.js"></script>
<script type="text/javascript" charset="utf-8">
// Wait for Cordova to load
//
document.addEventListener("deviceready", onDeviceReady, false);
var watchID = null;
// Cordova is ready
//
function onDeviceReady() {
// Update every 3 seconds
var options = { frequency: 3000 };
watchID = navigator.geolocation.watchPosition(onSuccess, onError, options);
}
// onSuccess Geolocation
//
function onSuccess(position) {
var element = document.getElementById('geolocation');
element.innerHTML = 'Latitude: ' + position.coords.latitude + '<br />' +
'Longitude: ' + position.coords.longitude + '<br />' +
'<hr />' + element.innerHTML;
}
// onError Callback receives a [PositionError](PositionError/positionError.html) object
//
function onError(error) {
alert('code: ' + error.code + '\n' +
'message: ' + error.message + '\n');
}
</script>
</head>
<body>
<p id="geolocation">Watching geolocation...</p>
</body>
</html>